Simple VB.Net Calculator

Table Of Contents
Summary
Introduction
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Summary

Hello, in this tutorial, am going to show you how to develop vb.net calculator in just few lines of code.  Attachment is available for download.
Introduction

Though this calculator can be developed using advance VB.Net coding, I have made it simple as I can for you and I to understand how the application will work without having to stress ourselves thinking of advance codes.
The program is been divided into two procedures which are 
AddDigits()
 and the 
Process()
. The 
AddDigits()
 procedure is used to key in value that will be display on the calculator's screen while the 
Process()
 procedure otherwise is used to perform calculation process and algorithm.
Some variables like num1, num2, res and opt e.t.c where declared generally.

Just as I said, I have made this program as simple as possible.

Let's start right away
1. Loading the Visual Studio environment

First of all, you should launch Visual Studio by either clicking on Start menu button or clicking on its icon from the desktop. Whichever way you use, you should see a similar screenshot below depending on the version of Visual Studio you have mine is 2012.



2. Click on File menu, then click on New>Project and similar window as below will show



3. Enter the File Name in this case "Calculator" in the file name box
4. Specify folder to save to
5. Click on Ok
And a blank form as below should show



**Change the backcolor of the form to crimson and place every other controls inside group control in VB.net

Now add all controls on the table below and set properties as follows



Controls
Properties


Label
Name: Label2
Text: Blank
Backcolor: crimson
ForeColor: White
Font-Weight:bold


TextBox
ReadOnly:True
Text:0


Button1
Name: btn8
Text: 8
Backcolor:grey


Button2
Name: btn9
Text: 9
Backcolor:grey


Button1
Name: btn7
Text: 7
Backcolor:grey

Public Class Form1
    Dim opt As String
    Dim num1, num2, iVal As Integer
    Dim res As Double
    Dim data As String
    Private Sub btn8_Click(sender As Object, e As EventArgs) Handles btn8.Click
        AddDigits(8)
    End Sub
    Private Sub btn9_Click(sender As Object, e As EventArgs) Handles btn9.Click
        AddDigits(9)
    End Sub

    Sub AddDigits(dVal As Integer)
        If txtdisplay.Text = String.Empty Then
            txtdisplay.Text = dVal
            data = data & dVal

        ElseIf Int(txtdisplay.Text) = "0" Then
            txtdisplay.Text = dVal
            data = data & dVal
        Else
            txtdisplay.Text = txtdisplay.Text & dVal
            data = data & dVal
        End If
        Label2.Text = data
    End Sub
    Sub Process(opt1 As String)
        If opt1 <> "=" Then
            num1 = Convert.ToInt32(txtdisplay.Text)
            txtdisplay.Text = ""
            opt = opt1
            data = data & txtdisplay.Text & opt
            Label2.Text = data

        Else
            num2 = Convert.ToInt32(txtdisplay.Text)
            If opt = "+" Then
                res = num1 + num2
            ElseIf opt = "/" Then
                res = num1 / num2
            ElseIf opt = "*" Then
                res = num1 * num2
            Else
                res = num1 - num2
            End If
            data = data & "=" & res
            Label2.Text = data
            txtdisplay.Text = res
        End If
    End Sub
    Private Sub btn7_Click(sender As Object, e As EventArgs) Handles btn7.Click
        AddDigits(7)

    End Sub

    Private Sub btn4_Click(sender As Object, e As EventArgs) Handles btn4.Click
        AddDigits(4)

    End Sub

    Private Sub btn5_Click(sender As Object, e As EventArgs) Handles btn5.Click
        AddDigits(5)

    End Sub

    Private Sub btn6_Click(sender As Object, e As EventArgs) Handles btn6.Click
        AddDigits(6)

    End Sub

    Private Sub btn1_Click(sender As Object, e As EventArgs) Handles btn1.Click
        AddDigits(1)

    End Sub

    Private Sub btn2_Click(sender As Object, e As EventArgs) Handles btn2.Click
        AddDigits(2)

    End Sub

    Private Sub btn3_Click(sender As Object, e As EventArgs) Handles btn3.Click
        AddDigits(3)

    End Sub

    Private Sub btn0_Click(sender As Object, e As EventArgs) Handles btn0.Click
        AddDigits(0)

    End Sub

    Private Sub btnplus_Click(sender As Object, e As EventArgs) Handles btnplus.Click
        Process(btnplus.Text)
    End Sub

    Private Sub btndivide_Click(sender As Object, e As EventArgs) Handles btndivide.Click
        Process(btndivide.Text)
    End Sub

    Private Sub btnmultiply_Click(sender As Object, e As EventArgs) Handles btnmultiply.Click
        Process(btnmultiply.Text)

    End Sub

    Private Sub btnequalto_Click(sender As Object, e As EventArgs) Handles btnequalto.Click
        Process(btnequalto.Text)

    End Sub

    Private Sub btnsubstract_Click(sender As Object, e As EventArgs) Handles btnsubstract.Click
        Process(btnsubstract.Text)
    End Sub
End Class

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